Add a magnifier lens to the image.

Add a magnifier lens to the image.

BUG=skia:

Committed: http://code.google.com/p/skia/source/detail?r=14424

[mtklein, 2014-04-28 19:53:16]

https://codereview.chromium.org/252993003/diff/20001/experimental/webtry/js/w...
File experimental/webtry/js/webtry.js (right):

https://codereview.chromium.org/252993003/diff/20001/experimental/webtry/js/w...
experimental/webtry/js/webtry.js:56: canvas.width=256;
Can we grab the w/h from currentImage?

https://codereview.chromium.org/252993003/diff/20001/experimental/webtry/js/w...
experimental/webtry/js/webtry.js:68: setTimeout(drawZoom, 33);
Tsk. Tsk.  Don't you know we're trying to make the world a beautiful 60Hz?

https://codereview.chromium.org/252993003/diff/20001/experimental/webtry/js/w...
experimental/webtry/js/webtry.js:76: ctx.drawImage(currentImage, clientX -
currentImage.x, clientY - currentImage.y, 32, 32, 0, 0, ctx.canvas.width,
ctx.canvas.height);
Took me a while and a reference to parse this line.  Maybe

ctx.drawImage(currentImage,
              clientX - currentImage.x, clientY - currentImage.y,  // src zero
              32, 32,                                              // src
dimensions
              0,0,                                                 // dst zero
              ctx.canvas.width, ctx.canvas.height);                // dst
dimensions
?

[jcgregorio, 2014-04-28 20:45:25]

https://codereview.chromium.org/252993003/diff/20001/experimental/webtry/js/w...
File experimental/webtry/js/webtry.js (right):

https://codereview.chromium.org/252993003/diff/20001/experimental/webtry/js/w...
experimental/webtry/js/webtry.js:56: canvas.width=256;
On 2014/04/28 19:53:17, mtklein wrote:
> Can we grab the w/h from currentImage?

These dimensions just need to be large enough that the squares representing
pixels show up as squares on the canvas, so it is independent of output image
size.

https://codereview.chromium.org/252993003/diff/20001/experimental/webtry/js/w...
experimental/webtry/js/webtry.js:68: setTimeout(drawZoom, 33);
I doubt it would be noticeable on the 32x32 grid. 

On 2014/04/28 19:53:17, mtklein wrote:
> Tsk. Tsk.  Don't you know we're trying to make the world a beautiful 60Hz?

https://codereview.chromium.org/252993003/diff/20001/experimental/webtry/js/w...
experimental/webtry/js/webtry.js:76: ctx.drawImage(currentImage, clientX -
currentImage.x, clientY - currentImage.y, 32, 32, 0, 0, ctx.canvas.width,
ctx.canvas.height);
On 2014/04/28 19:53:17, mtklein wrote:
> Took me a while and a reference to parse this line.  Maybe
> 
> ctx.drawImage(currentImage,
>               clientX - currentImage.x, clientY - currentImage.y,  // src zero
>               32, 32,                                              // src
> dimensions
>               0,0,                                                 // dst zero
>               ctx.canvas.width, ctx.canvas.height);                // dst
> dimensions
> ?

Done.

[mtklein, 2014-04-28 20:49:52]

lgtm

[jcgregorio, 2014-04-28 20:50:19]

The CQ bit was checked by jcgregorio@google.com

[commit-bot: I haz the power, 2014-04-28 20:50:35]

CQ is trying da patch. Follow status at
https://skia-tree-status.appspot.com/cq/jcgregorio@google.com/252993003/40001

[commit-bot: I haz the power, 2014-04-28 21:03:44]

Change committed as 14424